Real-time community meets the well bore

In the highly competitive landscape of today’s oil and gas market, the requirement to make the right decisions the first time is crucial to ensure optimal well performance and operational safety. As the industry manages the placement of wells in increasingly complex reservoirs, it is imperative to manage the vast and varied amounts of data generated in the wellbore environment.

Formation evaluation, completions engineering, and drilling have traditionally been seen as separate activities. However, the reality is that these disciplines are interrelated and directly influence one another. If integration is important in the earth model, it is even more critical in the well bore, whether drilling miles offshore through thousands of meters of salt and rock, executing complex multilateral wells in highly fractured carbonate reservoirs, or drilling high-angle/horizontal wells in search of unconventional resources.

Real-time operations allow instant prediction of problems to enable informed decision-making in tight time-frames that lead to optimal performance, lower costs, and safer operations. However, real time is not a single concept. Rather, the world of real time consists of three communities – formation evaluation, drilling, and completions engineering – all of which have very distinct needs. The volume of data and the frequency in which that data is streamed to the surface vary for each community. While most current geoscience evaluation software offerings are targeted toward the needs of the formation evaluation and completions engineering communities, the need to integrate the drilling community with the geoscience community presents a major challenge for subsurface oil and gas software developers because of the high-frequency, high-volume monitoring requirements needed for drilling operations.

Image and log data can be used to pick sedimentary facies. (Images courtesy of Schlumberger)

Interdisciplinary platform approach

To keep pace with the growing complexities associated with today’s reservoirs, a wellbore software platform capable of delivering science that enables workflows across the E&P lifecycle is required. The software platform must effectively manage all relevant data and the forecasting of future reservoir behavior as well as analyze uncertainty across the entire workflow. Additionally, the wellbore platform must allow seamless integration of the best ideas and innovations so users can leverage the science specific to the needs of their respective community.

The Techlog wellbore software platform enables the cross-domain collaboration needed to bridge the petrophysics, geoscience, drilling, and completions engineering communities to provide an integrated multidisciplinary workflow. The workflow uses the entire range of wellbore information for effective planning and execution of complex wells or the monitoring of completions, depending on the point in the asset life cycle. Data streaming into the software in real time – regardless of the source – provide complete and full workflows from the field to any location around the world.

It takes a community

Different disciplines have very different requirements with regards to real-time data transmission. The data obtained by each of these communities have the ability to influence operations as the data are acquired, but the frequency in which the data are transmitted and the overall volume of the data differ significantly.

Formation evaluation community. A complete understanding of formation properties is required to effectively and efficiently manage a reservoir. This derives from integration of the maximum amount of data that is acquired. The platform allows users to design custom workflows to generate meaningful interpretations, both quick-look and highly sophisticated in nature. An application within the wellbore software platform can be run in real time to improve the efficiency of operations and reduce time from drilling to analysis. This feature is not restricted to the predefined platform modules but also can be readily accessed by the user-defined scripting tools so that specific and bespoke solutions can be run in a given field. The formation evaluation community has the least stringent requirements when it comes to real-time data management in a wellbore software platform considering that data are typically streamed only once or twice a day and that the volume of data is relatively small.

The borehole shape can be reviewed with image data.

Completions engineering community. Once a well has been constructed and the completion is set, it can be equipped with downhole sensors that are used to provide a wide variety of data, such as pressure and temperature, fluid density and rates, and other downhole sensing information. Wells such as this are often referred to as smart wells and create the key data for digital operations. The software platform effectively manages all of these data, enabling real-time decision-making based on operating parameters or limits set in support of digital operations. The data are streamed to the surface on a frequent basis, typically many times throughout the day, but the volume of the data is fairly minimal compared to the data obtained during drilling operations.

Drilling community. During drilling operations, large volumes of data are being transmitted constantly throughout the day. The data are sent to the office and operations service centers, where these can be managed and monitored around the clock. Information pertaining to pore pressure, wellbore stability, and drilling engineering data (weight, ROP, pump conditions, equivalent circulating density, etc.) is streamed back to the surface from various sensors multiple times per second. The data obtained from these sensors play a critical role in the drilling process because of safety considerations. The overall safety of drilling operations is highly dependent on the condition of the well as it is being drilled.

Drilling parameters can be streamed into Techlog for display.

Ensuring safety. The wellbore stability workflow ensures safe and efficient drilling through real-time geomechanical analysis. The module supports the estimation of the mechanical earth model, including mechanical stratigraphy, static elastic properties, rock strength, and principal stress, as well as predicting failures based on a linear poroelastic model, and it is used to assess the safe mud weight window.

Another major challenge is the treatment of high-angle/horizontal well data. The wellbore software platform incorporates information regarding the environmental disturbances or artifacts commonly seen in these types of data. These effects are prevalent because drilling typically takes place along the formation bedding rather than perpendicular to it. Using the platform with the geosteering model-compare-update workflow in the Petrel E&P software platform, the value of log data acquired from high-angle horizontal wells is fully maximized, leading to maximum reservoir contact while ensuring drilling safety. This key workflow enables drilling engineers and geoscientists to manage well integrity at the wellbore scale in the wellbore software platform and keep the well bore optimally positioned in the reservoir in the Petrel 3-D reservoir perspective.

Real time in action

One major operator has incorporated both the Techlog wellbore software platform and the Petrel E&P software platform to enhance formation evaluation data. Schlumberger experts worked closely with the operator to create a workflow that streams log data into Techlog software, where borehole artifacts are removed to improve the log information. The corrected data are then transferred into Petrel software to update the geological model.

In Brazil, another operator used integrated petrophysics and geosteering reservoir characterization data for the development phase of an offshore carbonate reservoir. Traditional log data did not effectively capture textural differences that characterized the prolific zones. The formation evaluation challenge was to understand the multi-mineral composition of the rock to identify the largest production intervals.

Neural network technology aids in permeability prediction.

The real-time data were streamed from the rig to a full-time monitoring and decision team located at the operator’s headquarters to take advantage of the data to ensure drilling efficiency. Real-time measurements supported evaluation of net-to-gross and reservoir quality. Imagers were used to compute dips and adjust borehole inclination, while effective porosity was determined using neutron/density spectroscopy. Permeability was calculated using a neural network approach – the K.Mod module in Techlog. This module provided parameter prediction and log reconstruction using multilayer perception technology. Dedicated templates for visualizing the results and the associated uncertainty enhanced the petrophysicists’ productivity and provided quantitative estimates of the fit quality obtained. The updated models were then stored and applied to other wells.

Integrating the domains

Truly integrated and multidisciplinary workflows will drive solutions to the tough challenges associated with the reservoirs being exploited today. Technologies that bridge multiple disciplines support the cross-domain collaboration that is vital to the success of E&P activity. Access to real-time information from the drilling operation within the context of formation evaluation information allows diverse discipline experts to iterate on the fly to ensure reservoir optimization and, most importantly, operational safety.

To support these core objectives of ensuring reservoir optimization and operational safety in challenging reservoirs, the real-time communities – formation evaluation, completions engineering, and drilling – must work together. Hence the requirement for a well-bore software platform that can satisfy the data volume and data-streaming frequencies associated with each of these communities.